A Flash Of Time
by IAmThePoisonedYouth
Summary: The Doctor and Rose Tyler land in Central City, and are instantly seen as a threat, and when they meet the Scarlet Speedster, a battle of wits occur. {Based off Tumblr Fic}


**Author's Note: Based off a tumblr post, here's the weirdest crossover I will ever write.**

Creaking, whooshing groaning filled the crisp air of Central City as a mysterious blue box blinked in and out of vision, materialising in the middle of a park, drawing the attention of a couple of confused passersby, as well as perplexed discussions going through the air.

Unfortunately, this strangeness was not so bizarre for the residents of Central City as of late, having seen men who could control the weather with a mere thought and another who's skin burned up like fireworks, as well as many others.

Inside the box, a place that seemed like a million worlds squeezed inside a small, wooden blue shell, stood two people. One was a man, only not quite, who's blue eyes were swimming with a miraculous sense of wonder as his eyes fixated on the computer screen in front of him.

His companion, a London-bred blonde, queried, "Where are we?" she waited for him to answer, but the only one she received was the slight dimming of wonder in his eyes, "Doctor?"

"That's impossible…" the man mumbled, his Northern English accent tipped with concern.

The blonde frowned, "Doctor? What is it?"

"This is strange." he backed away, heading up the ramp whilst his companion eagerly followed him, brows knitting together in confusion.

He opened the door of his box, revealing the park in which they had landed in, as well as some rather terrified civilians.

"Oh." he stepped out of the box, then greeted the people with an awkward wave, "Oh. Hello. I'm The Doctor, and this is Rose Tyler." he gestured to his blonde friend, who unconsciously crept closer to him as the almost accusing eyes landed on her.

She laughed nervously, also giving a small gesture, "Hello."

Meanwhile, at S.T.A.R. Labs, a scientific research centre that was once the pinnacle of the town, Barry Allen sat with his friends Caitlin Snow and Cisco Ramon, mulling over the boredom of having a day off, as well as the horrors of entirely lacking a social life.

He heaved a sigh, almost wishing for something to happen so he could go and play hero instead of sit awkwardly with the girl whom he had caused to be a widow and the man who had almost lost his brother because of him.

Sometimes, the unbearable guilt of just existing crept up on Barry, and he hated it. He hated living, knowing that there were so many dead because of him. He had been the Flash for just under a year, and already, he had loved and lost, had held his own mother in his arms as she bled to death because he was _tooslowtooslowtooslow._

He noticed his hand was vibrating against the table when Cisco coughed, deviating his attention from his own self-deprecating thoughts.

"Sorry." he murmured, feeling the need to run, to not sit still, every atom in his body just wanting to move instead of remain frozen.

Sadly, some of the best remained frozen. The criminals and adversaries he couldn't defeat, the ones who had the upper hand. Their names ran through his mind, _MarkMardonLeonardSnartMickRoryAndEveryoneElse,_ and he sighed, shifting in his chair.

When the computer beeped, he felt a weight lift off his chest and practically blurred to the screen, the only thing restraining him was the thought that Cisco was already on it.

"Central City park, there's been a mysterious box, people say it just appeared." Cisco read out the report, then Barry nodded before flashing out, grabbing his suit in the process and knocking over several piles of paper.

Caitlin sighed, unimpressed, "You know, one day, he's not going to do that."

The Doctor looked at the growing crowd of people and tried to think of an excuse, cursing his nine hundred year old brain for thinking only of bananas in that moment. He was the cleverest man in the galaxy, but some of the things that came out of his noggin truly worried him.

"Doctor, we should go." Rose suggested, reaching to take his hand.

He was about to agree with her when suddenly, a streak of red flashed in front of him, and in shock, he stepped back onto Rose's toe, instantly turning when she shrieked.

"No, no." she assured, biting her lower lip to stem the pain, "I'm okay."

The streak thinned into the shape of a young man, and The Doctor noticed every single detail about him he could make out.

"Wow." was all he could think to say, "That is one amazing outfit."

The man rolled his eyes, sighing, "Come on, buddy, you're scaring the locals."

"Which locals are these exactly?" The Doctor asked, scratching his buzzed head as he attempted to be subtle.

He seemed only to irk the man in red, who replied, "What the hell are you talking about? Come on, you're under arrest." he touched the Doctor's shoulder.

"Oi!" Rose growled protectively, dark eyes widening in slight rage, "Let him go o-or I'll-"

The man in red scoffed, "You'll what?"

"I don't know, but I'll do _something!"_ she threatened, "Who the _hell_ do you think you are anyway?"

He looked confused for a second, "Wait. You don't know who I am?"

"Nope." The Doctor grinned, "No idea. Much more fun that way."

The man introduced himself, "I'm The Flash. Actually, what I am is confused. Are you for real? You haven't heard of me."

"Should I have?" The Doctor asked, then reached into the massive pockets of his leather jacket, "Hold on." he said, stretching until he found what he was looking for. He pulled out the black slip and opened it, revealing a white page of paper, "See. I'm Doctor Smith, and this is my assistant Rose Tyler. We're working on an experiment for-"

The Flash interrupted, looking confused, "This paper's blank."

"No, it's not." Rose argued, "I can see it, Doctor Smith and-"

The man in red arched an eyebrow, "Are you tricking me right now?"

"Ah. It seems your brain works quicker than most humans." The Doctor stated, "Well, that's never happened to me before."

The Flash tilted his head, "I've got no idea what you're even talking about, but you're under arrest."

"See, there's just one thing I've got to say about that." The Doctor gave a smirk, and The Flash noticed an object in The Doctor's hands.

It was small and silver, with a dark blue tip, and before he could blur and grab it, The Doctor pressed a button, and suddenly, everything started to shake. His very molecules began to tremble, and he saw the twosome rush back into their strange box. Gathering all his strength, he followed them, collapsing onto his knees as soon as he entered the strange place.

His head reared up, golden lightning dancing in the whites of his eyes as he fought the buzzing in his bones, it threatening to turn to pain.

Then, it stopped. Within a quick moment, between seconds even, the shaking simply ceased, and he looked around confusedly, hearing a groaning, roaring sound surround him.

It hadn't occurred to him just how big this place was, and he looked around, fear racing through his veins as the doors of the box shut. He tore back his cowl, dark hair bouncing up as the stress of leather crushing it lifted, and he couldn't help the curse that escaped him.

"Language." The Doctor chastised condescendingly, as if he was talking to a child.

Sadly, though, the other man wasn't The Flash in here. He was just plain old Barry Allen, and he was for sure, out of his element.

"Where…" he got to his feet and couldn't help spinning around to get a good look at where he was, trying to catch his breath, "Where am I?"

Rose asked her friend, "Oh, can I do it this time? _Pleaaase, Doctor?"_

"Fine." The Doctor said, "But we're not keeping him."

Rose smiled, "Well, this is the TARDIS, that stands for Time And Relative Dimension In Space, I'm Rose Tyler and this is The Doctor."

"What a-are you?" Barry asked, trying to keep a level head.

Rose replied, "Well, he's a Time Lord, and I'm… well, I'm human."

"T-Time Lord." Barry shuddered, "Okay. _Awesome._ I'm losing my _freaking mind here_."

Rose felt sorry for him in an instant and walked over to him, resting a hand on his shoulder, "You okay?"

"Well, I'm on board a crazy box thing that's bigger on the outside." he sighed, "But I'm the fastest man alive, so I should be used to crazy by now."

Rose gave a comforting smile, "You get used to it eventually. Can I get a name?"

"If I can remember it." Barry puffed out a laugh, then introduced himself, "Barry. Barry Allen."

The Doctor asked, "Where are you from, Barry Allen? I'll just drop you off, and then pop off."

"Um…" Barry's muddled mind picked out the words, "Central City, 2015. I was at S.T.A.R. Labs."

The Doctor tilted his head thoughtfully, "Sounds familiar. Hmm. Might've heard it in an advert somewhere. Oh well. Destination S.T.A.R Labs."

"Wait, this is a time machine." Barry stated, "Time and Relative Dimension In… Oh. Yeah. Space. Yippee."

There was some rocky turbulence, then blissful nothing, and Barry looked at the two confusedly.

"Are we here?" he asked.

Rose suggested, "Check outside. And I hope you've learned a valuable lesson."

"Not to run onto mystery ships. Okay." Barry nodded in acknowledgement, then opened the TARDIS doors, finding himself in one of the corridors in S.T.A.R Labs, and an uneasiness filled his stomach, as well as a desire to plead to The Doctor to help fix _his_ mistakes.

But Barry already knew the answer, and gave the two a silent nod before stepping out of the box. He took three steps and he heard the door close and the same whooshing groan from earlier fill the air, and when he turned back, the TARDIS was gone.

After a few minutes of lonely silence, Barry heard Cisco's voice in his comms unit, "Dude?"

He flashed into the lab, and both of his friends looked shocked to see him.

"You're okay!" Caitlin smiled, "Thank God. We heard you run into that box thing, then your comms just cut out and-" she stopped to pull him forward into a tight hug.

Barry grunted at the force of the hug, then wrapped his arms around her waist, squeezing back, "I'm alright." he assured, "And I think that I shouldn't be the only one having a day off. Come on guys, let's go out for a couple of drinks, I'll call Iris."

"Are you kidding me, _Barry Allen_ wants to have fun?" Cisco teased.

Barry nodded, finally being released by Caitlin and shrugged, "I guess I need it."

"Fine, then." Cisco smirked.

Caitlin laughed, "It's a deal."


End file.
